This invention relates to a light-sensitive silver halide color photographic material more emphasized in the interimage effect (hereinafter called I.I.E.) and a light-sensitive silver halide color photographic material improved in color reproducibility and sharpness thereby.
Generally speaking, a light-sensitive silver halide color photographic material has three kinds of silver halide emulsion layers for photography spectrally sensitized selectively so as to have sensitivity to blue light, green light and red light provided by coating on a support. For example, in the light-sensitive silver halide photographic material for color negative film, there are generally provided a blue-sensitive silver halide emulsion layer, a green-sensitive silver halide emulsion layer and a red-sensitive silver halide emulsion layer, in order, from the side exposed In addition, a yellow filter layer capable of bleaching is provided between the blue-sensitive silver halide emulsion layer and the green-sensitive silver halide emulsion layer for absorption of the blue light passed through the blue-sensitive silver halide emulsion layer. Further, it is usual to provide other intermediate layers for various special purposes between the respective emulsion layers and a final protective layer, as the outermost layer. It is also known to provide the respective light-sensitive silver halide emulsion layers in arrangements different from that as described above. Other arrangements include the use of a light-sensitive silver halide emulsion layer consisting of two or more layers having light sensitivity to substantially the same wavelength region to respective color lights but differing in sensitivity. In these light-sensitive silver halide color photographic materials, the exposed silver halide grains are developed with, for example, an aromatic primary amine type color developing agent, and the dye image is formed through the reaction between the oxidized product of the color developing agent formed and a dye forming coupler. In this method, for formation of dye images of cyan, magenta and yellow, phenol or naphthol type cyan couplers, 5-pyrazolone type, pyrazolinobenzimidazole type, pyrazolotriazole type, indazolone type or cyanoacetyl type magenta couplers and acylacetamide type yellow couplers are used, respectively. These dye forming couplers are contained in the light-sensitive silver halide emulsion layer or the developing solution. The present invention is suitable as a light-sensitive silver halide color photographic material containing the coupler previously made non-diffusible in the silver halide emulsion layer.
In recent years, marked improvement can be seen in image quality of light-sensitive silver halide color photographic materials, but color reproducibility is not yet satisfactory. Particularly, there are involved a number of insufficient points in reproduction of saturation of color (chroma). Conceivable causes therefore may be the spectral characteristics of the color formed dye obtained from the coupler (absence of sufficient absorption in the specific wavelength region or presence of unnecessary absorption in another wavelength region), color mixing due to migration of spectral sensitizing dye, or otherwise color mixing of the color developing agent with the oxidized product.
One of the characteristics demanded for the light-sensitive color photographic material is absence of turbidity in color, namely high color purity, during formation of a dye image in one color-sensitive layer by color formation of other color-sensitive layers by the oxidized product of the color developing agent formed therein.
In the prior art, it has been known to provide an interception layer (IL) which is also called the intermediate layer between different color-sensitive layers and add a scavenger of the oxidized product of the color developing agent or a non-color-indicating coupler in said interception layer (IL), or add a diffusion preventive for the senstizing dye, etc. such as fine particulate silver halide grains, a cationic hydrophilic synthetic polymer, a polymer latex, etc. in the interception layer (IL). However, even by these methods, no fully satisfactory color reproducibility has been achieved.
As another method for improvement of color mixing, a technique of automatic masking by use of a colored coupler is known and used routinely in negative light-sensitive silver halide color photographic materials, but the level of color reproducibility is far from satisfactory.
The techniques for improving color reproducibility by emphasizing I.I.E. with the use of DIR couplers have been known, and various compounds are used as these DIR compounds. For example, there may be included the so-called DIR couplers which form color forming dyes through the oxidized product of a color developing agent simultaneously with release of a developing inhibitor during development, the so-called DIR substances which release a developing inhibitor through the reaction with the oxidized product of a color developing agent but do not form a color forming dye, those which can release directly or indirectly a developing inhibitor through the reaction with the oxidized product of a color developing agent as disclosed in Japanese Provisional Patent Publications No. 145135/1979, No. 154234/1982, No. 162949/1983, No. 205150/1983, No. 195643/1984, No. 206834/1984, No. 206836/1984, No. 210440/1984 and No. 7429/1985 (hereinafter called timing DIR compounds). In the present specification, those exhibiting the above DIR effect are called comprehensively as the DIR compounds.
When these DIR compounds are used in light-sensitive silver halide color materials, developing inhibitors can be released from DIR compounds during development to obtain the effect of inhibiting development in other silver halide emulsion layers, namely I.I.E. Particularly, DIR compounds capable of releasing the so-called diffusive inhibiting groups or diffusive developing inhibitor precursors are effective. They have been used for silver halide color films in these days to give some effects. However, due to strong directional tendency of I.E.E. (for example, strong in the direction from a blue-sensitive silver halide emulsion layer to a green-sensitive silver halide emulsion layer, but weak in the opposite direction), although improvement of saturation (chroma) of a specific color may be expected, an undesirable effect of "dislocation in hue" is accompanied therewith. Also, with respect to diffusiveness, since the inhibiting effect acts most strongly on the added layer, and therefore problems are involved such as lowering in gamma (.gamma.), lowering in sensitivity, lowering in color formed density, etc. Thus, it is difficult to use an amount which can give sufficient effects to other layers.
The techniques for emphasizing I.I.E. from a color-sensitive layer to a different color-sensitive layer with the use of the so-called diffusive DIR compound are disclosed in Japanese Patent Publication No. 47379/1980, Japanese Provisional Patent Publications No. 93344/1982, No. 56837/1982 and No. 131937/1984. Even by use of these techniques, only unsatisfactory improvement of color reproducibility can be expected under the present situation.
Accordingly, a first object of the present invention is to improve color reproducibility, particularly reproduction of saturation (chroma), by making greater I.I.E. in both directions between different color-sensitive layers.
On the other hand, it has been known to improve sharpness of an image, when I.I.E. is created by use of the so-called diffusive DIR compound as disclosed in the above patent publications or specifications.
This is due to improvment of color contrast accompanied with I.I.E, which is the edge effect between layers in addition to the edge effect in the added layer.
Accordingly, a second object of the present invention is to improve sharpness of an image by emphasizing I.I.E. in both directions by use of a DIR compound according to a suitable method.